What is the correct way to use CFontDialog common dialog? - mfc

Question

I recently change the relationship between the window extent and the view port of an MFC application, and, since then, every time I change my application font size, the selected font become supper gigantic even if I chose the smallest of all font size.
(EDIT: I noticed that CFontDialog::GetSize() return a size that is ten times the size chosen in the dialog. Is that a usual behaviour ? If not what could make the dialogue return such a value? Although I am not sure, but it seem this multiplication of size seem to be my problem. How do I get CFontDialog::GetSize() to return the actual selected size, if that indeed is the problem?)
What am I doing wrong? What is the correct way to use CFontDialog ?
Shown next is a snippet of the font changing code:
CClientDC dc(pView);
pView->OnPrepareDC(&dc)
pLastFont = pLastText->GetFont();
oldColor = pLastText->GetColor();
LOGFONT logFont = (LOGFONT) (*pLastFont);
CFontDialog fontDialog(&logFont);
CSize szPrevSize;
//Some missing codes
MyFigure *pMyFigure;
if(dynamic_cast<MyTextFigure*>(pMyFigure) != NULL)
{
if(dynamic_cast<MyTextBoxFigure*>(pLastText) != NULL)
{
MyTextBoxFigure *pTextBox = dynamic_cast<MyTextBoxFigure*>(pLastText);
szPrevSize = pTextBox->GetTextSize();
}
}
else if(dynamic_cast<MyTableFigure*>(pMyFigure) != NULL)
{
MyTableFigure *pTableFigure = dynamic_cast<MyTableFigure*>(pMyFigure);
TCell *pCell = (TCell *)*pTableFigure;
szPrevSize = pCell->GetTextSize();
}
fontDialog.m_cf.rgbColors = (COLORREF) oldColor;
if (fontDialog.DoModal() == IDOK)
{
fontDialog.GetCurrentFont(&logFont);
MyFont newFont = (MyFont) logFont;
MyColor newColor = (MyColor) fontDialog.GetColor();
pMyFigure->SetFont(newFont, &dc);
pMyFigure->SetColor(newColor);
}
Please note that MyFont is a wrapper around the LOGFONT structure and has an operator that enable cast to LOGFONT. Also note that MyFigure class has a MyFont data member that is set by the member function SetFont.
The following code shows how the relationship between the view port and the window extent was set.
void CDisplayView::OnInitialUpdate()
{
CRect rcClient;
GetClientRect(&rcClient);
CClientDC dc(this);
dc.SetMapMode(MM_ISOTROPIC);
CSize szWindow(m_pAppDoc->GetZoomRatio() * SCALE_RATIO * dc.GetDeviceCaps(HORZRES),m_pAppDoc->GetZoomRatio() * SCALE_RATIO * dc.GetDeviceCaps(VERTRES));
CSize szViewport(dc.GetDeviceCaps(HORZRES),dc.GetDeviceCaps(VERTRES));
dc.SetWindowExt(szWindow);
dc.SetViewportExt(szViewport);
dc.DPtoLP(&rcClient);
//And so on
}
ZoomRatio is 1, an SCALE_RATIO is 1.2
The assignment operator is:
MyFont& MyFont::operator=(const MyFont& font)
{
if (this != &font)
{
m_logFont = font.m_logFont;
}
return *this;
}
P.S.
The summary of the code is:
LOGFONT OldlogFont ;
LOGFONT newLogFont;
COLLORREF OldColorref;
COLORREF newColorref;
CFontDialog fontDialog(&OldlogFont);
fontDialog.m_cf.rgbColors = oldColorref;
if (fontDialog.DoModal() == IDOK)
{
fontDialog.GetCurrentFont(&OldlogFont);
newLogFont = OldlogFont;
newColorref = fontDialog.GetColor();
}
The focus here is the LOGFONT structure.
The user selected value is gotten with old logfont then assigned to new logfont.
For debugging purposes, I retrieved the size of the selected font and was shocked to find that it is ten times the size that I selected after lunching the CFontDialog for use in my application i.e
LOGFONT OldlogFont ;
LOGFONT newLogFont;
COLLORREF OldColorref;
COLORREF newColorref;
CFontDialog fontDialog(&OldlogFont);
fontDialog.m_cf.rgbColors = oldColorref;
if (fontDialog.DoModal() == IDOK)
{
fontDialog.GetCurrentFont(&OldlogFont);
newLogFont = OldlogFont;
newColorref = fontDialog.GetColor();
int iFontSize = fontDialog.GetSize();
//when I selected a font size of 10 from the dialog, what I get here in my code is 100.
}

Answer 1

This is how I do it:
void CExportSettingsDlg::OnBtnSelectFont()
{
CClientDC dc(this);
m_plfCurrentFont->lfHeight =
-MulDiv(m_plfCurrentFont->lfHeight, dc.GetDeviceCaps(LOGPIXELSY), 72);
CMyFontDialog dlgFont( m_plfCurrentFont );
dlgFont.m_cf.Flags |= CF_NOSCRIPTSEL;
dlgFont.m_cf.rgbColors = m_crCurrentFontColour;
if( dlgFont.DoModal() == IDOK)
{
m_plfCurrentFont->lfHeight = -(dlgFont.GetSize()/10);
// We must retrieve the font colour into the correct variable.
// The logfont is already correct because we passed in the
// logfont pointer into the font dialogue.
switch( m_iFontType )
{
case FONT_TITLE:
m_sSettings.crTitleFontColour = dlgFont.GetColor();
break;
case FONT_HEADING:
m_sSettings.crHeadingFontColour = dlgFont.GetColor();
break;
case FONT_GENERAL:
m_sSettings.crGeneralFontColour = dlgFont.GetColor();
break;
case FONT_EVENT:
m_sSettings.crEventFontColour = dlgFont.GetColor();
break;
case FONT_NOTES:
m_sSettings.crNotesFontColour = dlgFont.GetColor();
break;
}
// Update display
SetSampleFont();
// Html Preview
UpdatePreviewHtml();
}
}
If it does not answer your question I will remove the answer. Notice how I set the font size at the start of the code.
If you read up on the MSDN for GetSize it states:
The font's size, in tenths of a point